Ackles, who plays Dean Winchester, told E! Online: "Essentially the big topic [this season] is there's a new evil in the world and the boys are going to have to combat it by pooling their [meagre] resources."

He added: "It's going to be a difficult situation for both [Dean and his brother Sam]."

Ackles also suggested that early episodes of the new season will focus more on younger Winchester brother Sam (Jared Padalecki).

"Sam is dealing with more of a personal issue than Dean," he explained.